ChemInform Abstract: Highly Enantioselective Organocatalytic Cascade Reaction for the Synthesis of Piperidines and Oxazolidines.

✍ Scribed by Sylva Cihalova; Guillem Valero; Jiri Schimer; Marek Humpl; Martin Dracinsky; Albert Moyano; Ramon Rios; Jan Vesely

• Publisher: John Wiley and Sons
• Year: 2012
• Weight: 65 KB
• Volume: 43
• Category: Article
• ISSN: 0931-7597
• DOI: 10.1002/chin.201213164

✦ Synopsis

Highly Enantioselective Organocatalytic Cascade Reaction for the Synthesis of Piperidines and Oxazolidines. -Organocatalyzed Michael addition of amidomalonates, e.g. (I) and (VI), towards enals (II) followed by intramolecular hemiaminal formation provides enantioenriched piperidine derivatives (III) and (VII), resp., in up to 99% optical purity. The reaction is strongly influenced by steric bulk around the amide nitrogen [cf. (IX)]. In the presence of an N-(hydroxyethyl) substituent at the amidomalonate, a combination of organocatalytic cascade Michael-cyclization reaction with a further cyclization step is successfully applied to the synthesis of oxazolidinopiperidine derivatives (XIII).